<template>
    <div v-if="!item.hidden" class="menu-wrapper">
        <!--如果是独生子节点或者是叶子节点显示为超链接  -->
        <template
            v-if="
                hasOneShowingChild(item.children, item) &&
                (!onlyOneChild.children || onlyOneChild.noShowingChildren) &&
                !item.alwaysShow
            "
        >
            <router-link
                v-if="onlyOneChild.meta"
                :to="resolvePath(onlyOneChild.path)"
            >
                <el-menu-item
                    :index="resolvePath(onlyOneChild.path)"
                    :class="{ 'submenu-title-noDropdown': !isNest }"
                >
                    <item
                        :icon="
                            onlyOneChild.meta.icon ||
                            (item.meta && item.meta.icon)
                        "
                        :title="onlyOneChild.meta.title"
                    />
                </el-menu-item>
            </router-link>
        </template>

        <!-- 文件夹节点 -->
        <el-submenu
            v-else
            ref="subMenu"
            :index="resolvePath(item.path)"
            popper-append-to-body
        >
            <template v-slot:title>
                <item
                    v-if="item.meta"
                    :icon="item.meta && item.meta.icon"
                    :title="item.meta.title"
                />
            </template>
            <!-- 递归 -->
            <sidebar-item
                v-for="child in item.children"
                :key="child.path"
                :is-nest="true"
                :item="child"
                :base-path="resolvePath(child.path)"
                class="nest-menu"
            />
        </el-submenu>
    </div>
</template>

<script>
import path from 'path'
import Item from './Item'

export default {
    name: 'SidebarItem',
    components: { Item },
    props: {
        // route object
        item: {
            type: Object,
            required: true,
        },
        isNest: {
            type: Boolean,
            default: false,
        },
        basePath: {
            type: String,
            default: '',
        },
    },
    data() {
        this.onlyOneChild = null
        return {}
    },
    methods: {
        hasOneShowingChild(children = [], parent) {
            const showingChildren = children.filter((item) => {
                if (item.hidden) {
                    return false
                } else {
                    // 如果只有一个子菜单时设置
                    this.onlyOneChild = item
                    return true
                }
            })

            // 当只有一个子路由，该子路由默认显示
            if (showingChildren.length === 1) {
                return true
            }

            // 没有子路由则显示父路由
            if (showingChildren.length === 0) {
                this.onlyOneChild = {
                    ...parent,
                    path: '',
                    noShowingChildren: true,
                }
                return true
            }

            return false
        },
        resolvePath(routePath) {
            return path.resolve(this.basePath, routePath)
        },
    },
}
</script>